* {
    padding:0;
    margin:0
}
.banner {
    width:100%;
    height:600px;
    font-size:0;
    overflow:hidden;
    position:relative
}
.banner_img {
    width:100%;
    height:450px;
    position:absolute;
    left:0;
    top:0
}
.banner_img li {
    width:100%;
    height:450px;
    display:inline-block;
    background-position:center;
    background-repeat:no-repeat;
    float:left;
    list-style:none
}
.banner_list {
    height:50px;
    top:400px;
    position:relative;
    margin:0 auto;
    z-index:1
}
.banner_list span {
    display:block;
    cursor:pointer;
    width:14px;
    height:14px;
    border-radius:50%;
    border:3px solid #555;
    float:left;
    margin:0 5px
}
.banner_list .spcss {
    border:3px solid #9acd32
}
.banner_left {
    position:absolute;
    height:90px;
    width:60px;
    top:50%;
    left:-60px;
    background-color:rgba(73, 72, 62, .6);
    margin-top:-45px;
    text-align:center;
    transition:all .5s;
    z-index:2
}
.banner_left:hover {
    background-color:rgba(73, 72, 62, .9)
}
.banner_right {
    position:absolute;
    height:90px;
    width:60px;
    top:50%;
    right:-60px;
    background-color:rgba(73, 72, 62, .6);
    margin-top:-45px;
    text-align:center;
    transition:all .5s;
    z-index:2
}
.banner_right:hover {
    background-color:rgba(73, 72, 62, .9)
}
.banner_left img {
    margin-top:22px
}
.banner_right img {
    margin-top:22px
}